< Chap. U. 



OPHEYS APIFEEA. 



53 



stigma. The anther-cells naturally open soon aftei 

 the flower is fully expanded, and the thick ends of 

 the pollen-masses then fall out, the yiscid discs still, 

 remaining in their pouches. Slight as is the weight 

 of the pollen-masses, yet the caudicles are so thin and 

 quickly become so flexible, that in the course of a few 

 hours they sink down, until they hang freely in the air 



Fig. 8. 



Ophbts atifeba, ok Bee Ophkts. 



a. anther. 



;: /. labellum. • 



A. Side view of flower, with the 

 upper sepal and the two upper 

 petals removed. One pollinium, 

 with its disc still in its pouch, 

 is represented as jast failing 



out of the anther-cell ; and 

 the other has fallen almost to 

 its full' extent, opposite to the 

 hidden stigmatic surface. 

 B. Pollinium in the. position in 

 which it lies embedded. , 



(see lower pollen-mass in fig. A) exactly opposite to 

 and in front of the stigmatic surface. In this position 

 a breath of air, acting on the expanded petals, sets 

 the flexible and elastic caudicles vibrating, and they 

 almcJSt immediately strike .the viscid stigma, and, 

 being there secured, impregnation is effected. To 

 make sure that no other aid was requisite, though 



